The present invention relates to fullerenic structures and such structures tethered to carbon materials.
Fullerenic structures are carbon compounds that include closed-caged compounds such as fullerenes and nanotubes. One of the first fullerenes discovered was the version containing 60 carbon atoms (C60) made up of adjacent carbon pentagon and hexagon rings. Other fullerenes such as C36, C70, and C90 have been observed and analyzed. It has been speculated that fullerenic structures both smaller than and larger than C60 exist in, for example, combustion-generated soot.
Because fullerenic structures are small (C60 has a diameter of approximately 7 Å) and typically occur in very low concentrations in soot, their presence is difficult to detect. Furthermore, fullerenes are difficult to detect and characterize because they are often very strongly bound to, or within, the material with which they are condensed in the synthesis process thereby preventing easy removal for chemical analysis. Examples are fullerenes smaller than C60 all of which necessarily contain adjacent pentagons in their structure and are strongly curved and strained and hence more interactive leading to strong bonding. Similarly, fullerenes larger than may also be strongly bonded to other structures because the size of larger fullerenes facilitates extensive contact thereby increasing the opportunity for bonding interactions.
It has been suggested that fullerenes bound to carbon black pigment would be useful for making an improved ink for use in, for example, an inkjet printer. See, Japanese Laid Open Publication no. 11-140342, published May 25, 1999. This reference, however, does not establish the chemical bonding of fullerenes to carbon black.